1. Field of the Invention
The present invention relates to an application apparatus and an inkjet recording apparatus, and more particularly to an application apparatus and inkjet recording apparatus for applying to a medium a liquid in which a treatment agent having a function of aggregating or insolubilizing a coloring material by reacting with an ink is dissolved.
2. Description of the Related Art
In an inkjet recording apparatus which forms an image by ejecting ink droplets, if a color image is formed by using inks of a plurality of colors, then there is a possibility that color bleeding occurs. Color bleeding of this kind reduces the quality of the image and therefore preventative measures of various kinds have been proposed. As one such measure, a method is known in which a treatment liquid having a function of aggregating or insolubilizing the coloring material in an ink by reacting with the ink is applied previously to a medium, and an image is formed by ejecting ink onto the medium to which this treatment liquid has been applied. According to this method, the coloring material in the ink droplets aggregates immediately after the droplets land on the medium, and therefore even if other ink droplets are ejected onto adjacent positions, there is no combination between the respective coloring materials and it is possible effectively to suppress the occurrence of color bleeding.
The treatment liquid can be applied by using either an application roller or an inkjet head. For instance, an application roller on which treatment liquid has been deposited on the circumferential surface thereof is abutted against the medium and treatment liquid is thereby applied to the medium (see, for example, Japanese Patent Application Publication No. 2007-83180, Japanese Patent Application Publication No. 2007-117806, or Japanese Patent Application Publication No. 2000-37942). Alternatively, treatment liquid is ejected from an inkjet head onto the medium which is traveling, and the treatment liquid is thereby applied to the medium (see, for example, Japanese Patent Application Publication No. 2004-291627).
If an image is formed using a treatment liquid of this kind, then in order to display a sufficient aggregating or insolubilizing action, the treatment liquid should be applied in such a manner that a sufficient amount of the aggregation promoting component or insolubilization promoting component contained in the treatment liquid remains on the medium. Therefore, it is necessary to apply a large amount of treatment liquid in order that a sufficient amount of aggregation promoting component or insolubilization promoting component remains on the medium after application. It is especially necessary to apply a large amount of treatment liquid in cases where the liquid is applied to a medium having high permeability, such as normal paper.
However, if a large amount of treatment liquid is applied to the medium, then there are possibilities that the medium curls and deforms, ultimately causing a decline in the quality of the image.